This invention relates to gas turbine engines for aircraft and particularly to the support means and the construction of the tail pipe plug and convoluted lobe mixer.
It has been customary to attach the tail pipe plug of the jet engine at its forward end to the turbine exhaust case so that it extended axially toward the rear of the engine. Further, accepted practice was to similarly attach the lobe mixer to the turbine exhaust case by weldment or bolting. Thus each unit would include its own support system and necessitated adding support structure to the turbine exhaust case.
Obviously, for maintenance purposes, having two independent attaching means requires the operator the dual task of removing each unit separately. This is not only cumbersome but requires all the separate hardware required for attachment purposes. Moreover, in existing engine installations where it is desirable to retrofit the engine with the lobe mixer for noise reduction purposes, it becomes a major task to rework the turbine exhaust case to accommodate the mixer.
I have found that I can obviate the problems noted above by combining the mixer and plug as a single unit and attaching these units to the engine case rather than the turbine exhaust case. The unit can then be slip jointed to the exhaust case which has the additional advantage of reducing the stresses occasioned by thermal growth.
A feature of this invention is to combine the tail pipe plug and lobe convoluted mixer of a gas turbine engine into a single integral unit and having a single point attachment to the engine case rather than the turbine exhaust case. Slip joints in proximity to the case allow for easy assembly and disassembly and improvements occasioned by thermal growth.
An advantage of the single unitary assembly permits the retrofitting of existing engines without necessitating the reworking of the turbine exhaust case.
Other features and advantages will be apparent from the specification and claims and from the accompanying drawings which illustrate an embodiment of the invention.